Who betrayed him,
‘You have said so.’”
ἀποκριθεὶς δὲ Ἰούδας ὁ παραδιδοὺς αὐτὸν εἶπεν Μήτι ἐγώ εἰμι, Ῥαββεί; λέγει αὐτῷ Σὺ εἶπας.
This is unique to Matthew, who recounted that Judas (ἀποκριθεὶς δὲ Ἰούδας), the one who was betraying Jesus (ὁ παραδιδοὺς αὐτὸν εἶπεν), addressed Jesus, calling him Rabbi (Ῥαββε), and not just teacher or lord. Judas responded that it surely was not him (εἶπεν Μήτι ἐγώ εἰμι). However, Jesus replied that he Judas had said it, so it must be so (λέγει αὐτῷ Σὺ εἶπας). This is a clear identification of Judas as the betrayer.